Characterization of apparent molecular weight distributions of soluble organics in wastewater following chemical treatment

Chemosphere ◽  
1979 ◽  
Vol 8 (6) ◽  
pp. 345-352 ◽  
Author(s):  
Hideki Tatsumoto ◽  
Shigeru Kobayashi ◽  
Nicholas L. Clesceri
2002 ◽  
Vol 75 (5) ◽  
pp. 853-864 ◽  
Author(s):  
Judit E. Puskas ◽  
Christophe Paulo ◽  
Volker Altstädt

Abstract Structure-property relationships were investigated in hyperbranched polyisobutylenes, in comparison with commercial linear butyl rubber. The gel-free, soluble hyperbranched polyisobutylenes, synthesized by living carbocationic polymerization, had molecular weights, Mw≈400,000 to 1,000,000 g/mol, molecular weight distributions, MWD ≈1.2 to 2.6, and branching frequencies, BR ≈ 4 to 60. The mechanical and viscoelastic characterization of these polymers revealed interesting properties, including the characteristics of crosslinked rubbers.


1986 ◽  
Vol 18 (4) ◽  
pp. 361-366 ◽  
Author(s):  
Yushu Matsushita ◽  
Kunio Shimizu ◽  
Yasushi Nakao ◽  
Haruhisa Choshi ◽  
Ichiro Noda ◽  
...  

1976 ◽  
Vol 49 (2) ◽  
pp. 303-319 ◽  
Author(s):  
M. Morton ◽  
L. J. Fetters ◽  
J. Inomata ◽  
D. C. Rubio ◽  
R. N. Young

Abstract The results of this study are the first to show that high-1,4 linear α,ω-dihydroxypolydienes can be synthesized with (a) predictable molecular weights, (b) narrow molecular weight distributions, and (c) high functionalities. Using the functionalized polyisoprenes prepared in this work, a series of networks was prepared with a purified triisocyanate as the chain linking agent. The soluble fraction in these networks ranged from 4.6 to 1.6 per cent. The characteristics and physical properties of these networks will be the subject of a forthcoming publication.


e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Aurica Farcas ◽  
Valeria Harabagiu

AbstractThis paper is devoted to the preparation and characterization of new phenanthroline-triether copolymers with rotaxane architecture by reaction of complexes of α- or β- cyclodextrin and tri(ethylene glycol) ditosylate with 2,9-di(4-hydroxyphenyl)-1,10- phenanthroline, which is large enough to prevent dethreading of cyclodextrin molecules. Comparative 1H-NMR analysis of tri(ethylene glycol) ditosylate complexes and of rotaxane copolymers evidenced the lower cyclodextrin content in rotaxane copolymers as compared to the calculated values. The rotaxane copolymers present bimodal molecular weight distributions attributed to the separation of the fractions with different content of cyclodextrin threaded on the copolymer chain. As evidenced by thermogravimetric analysis, the rotaxane copolymers show higher thermal stability than its non-complexed homologue.


2015 ◽  
Vol 815 ◽  
pp. 477-482
Author(s):  
Wei Xing Chen ◽  
Yong Qiang Gu ◽  
Chun Yan Luo ◽  
Xiao Long Zhang

Three kinds of poly (3-alkylthiophene), such as poly (3-butylthiophene) (P3BT), poly (3-hexylthiophene) (P3HT) and poly (3-dodecylthiophene) (P3DDT) were prepared by the Grignard Metathesis Method (GRIM). Their chemical structures are characterized by FTIR,1H-NMR and GPC.1H-NMR result shows that regioregular structure of these polymers is relatively higher. The GPC results show that the molecular weight of the polymers is 8.42×104, 1.06×105and 1.21×104g/mol with molecular weight distributions of 1.41, 2.18 and 1.18, respectively. The DSC result shows that the glass transition temperature of three kinds of polymers is 120.8, 146, 118 °C, respectively. UV absorption spectrum and fluorescence spectroscopy of three polymers in THF solution show that the maximum absorption wavelength is 448 nm, 470 nm, 390 nm, and the maximum emission wavelength is 531, 535, 527 nm with the band gap of 2.06, 1.86, 2.21 eV, respectively.


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